I am in the process of repainting my deck. I'd like to have a protective layer (like clearcoat on a car) that will allow easier cleanup, and would help to pretect the new paint. Is polyurethane appropriate for the job?

  • 2
    Polyurethane will not hold up to sunlight. – uncle brad Sep 14 '11 at 13:35
  • 1
    That is nonsense. There are aliphatic polyurethanes which hold up to UV (for instance made from HDI: hexamethylene diisocyanate), and there are aromatic polyurethanes which don't, like those made with TDI (toluene diisocyanate). – Kaz Mar 1 '13 at 0:16

What you're looking for is Spar Urethane. Polyurethane is not good for outdoor use. Spar urethane will hold up the UV rays better.

  • isn't spar urethane even more slippery than polyurethane? – Mike Pennington Jan 15 '12 at 23:04

I don't ever like film finishes (whether paint or poly or varnishes) for horizontal exterior surfaces. Water and sun will win. Then you must remove chipped paint/finish before renewing

The use of penetrating transparent or semi-opaque exterior rated stains, will breath and last longer. Overcoats can be made after washing and drying the surface.


There are additives you can add to a floor coating which reduce slipperiness, such as polypropylene beads.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.